Priming layers are used when bonding or coating two different materials together. One objective of the priming layer is to control the level of adherence of one material to another. The priming layer can be used to increase bond strength between two layers.
Where a coating is applied to a substrate and the composition of the coating does not have a natural affinity for the substrate, a primer layer can be used. Materials such as polyethylene terephthalate or polyolefins have well known problems in having coatings adhered thereto.
As adhesives are being designed with higher and higher adhesion to adherents and or target surfaces, the need for better and better priming is recognized to provide the required bond strength between the backing and the adhesive of these adhesive articles. The ability to provide higher strength primers or tie layers on specific target backings enables the creation of new adhesive articles having aggressive adhesives.